Motherboard and PCI-e slots

Discussion in 'Hardware' started by 2mTrader, Jan 21, 2011.

  1. 2mTrader


    Hoping someone can explain PCI-e slots to me. I am building a new trading system, I have two Nvidia Quadro NVS 295 graphics cards (so I can run 4 monitors) and I am wondering what PCI-e slots I need on the motherboard. Basically I don't understand the difference between the different sorts of PCI express slots and whether or not it makes any difference to these cards.

    The motherboard I am looking at is a Gigabyte GA-H67M-D2 H67 Socket 1155 GB (I will be using an Intel i5 4 core processor)

    It has the following PCI-e slots:
    1 x PCI Express x16 slot, running at x16 (PCIEX16)
    1 x PCI Express x16 slot, running at x4 (PCIEX4)
    2 x PCI Express x1 slots

    Will the above board suffice? will I be able to expand to 4 cards in the future (use up all 4 slots)? or do I need to find a board that has 2 x PCI Express x16 slots, running at x16?
  2. This mobo should suffice for your 2, 295s.. they both are x16, right?

    The difference in PCIE slots is just "size of the mounting connector". x1 is short, x16 is the longest. And obviously a long connector won't fit into a short slot. (There's an exception to this, but one not usually seen.)

    As for trusting that you could expand to 4 cards later... you'd have to depend upon the x1 slots to run video cards. While that is SUPPOSED to work, it doesn't always. To be safe, you should get a mobo with 4, x16 slots. For trading it doesn't matter how many lanes they're wired for.
  3. Is there a noticeable difference in charting between the legacy PCI slot and the new PCI-e?
  4. No. PCI bandwidth is 100-133 MB/s, all shared by the number of mounted devices. PCIE has bandwidth of 500 MB/lane. (x1 = 1 lane... x16 = 16 lanes.) While PCIE can handle many times more data, the data stream for trading is very low... often less than 100 kb/s.
  5. 2mTrader


    Thank you for you help Scataphagos, that is exactly the information I was after.

  6. To answer the first question, you didn't indicate whether your NVS 295 cards are made for PCIEX16 or PCIEX1. Some vendors produce cards with the same model number but fit on different slots (e.g. x1 or x16 or PCI or AGP). That motherboard you mentioned can only house 2 NVS 295 if they are PCIEX1 not X16.

    Second question - if you plan to run 4 cards eventually, you would save yourself some potential headaches by using the same slot types (e.g. all PCI Express x16). Mixing slot types for display cards is usually not a good thing. Mixing makes is also a bad idea too generally. Pick some motherboard that has more slots.

    For example, the following motherboard has 7 PCIe X16 slots. But it will not work for you because you are using an Intel i5 chip.,2688-6.html
  7. While I agree about "mixing makes"... it's likely less potentially troublesome if you have the same number of x16 slots as you want to run video cards... so long as the cards work together properly, whatever slot they use doesn't make any difference.

    I'm currently using an x1 card (in an x8 slot) along with 2, x16s, and the displays all look the same. Before PCIE, we all ran AGP + PCI and that was fine, too.

    One of the potential troubles today is trying to run an x1 video card from either an x1 or x16 slot. That's SUPPOSED to work, but it doesn't always. x1 cards, however, seem to always work from x4 or x8 slots. I have no explanation for this inconsistency.
  8. 2mTrader


    Hi Bolimomo - they are PCIEX16 cards.
  9. 2mTrader: you have 2 PCIX16 cards. The motherboard you mentioned only has 1 PCIX16 slot. I am not sure if it will work because the other one is PCIX16 slot running at X4.

    Scataphagos: I am not saying mixing slot types won't work. Personally I just will avoid it to save some potential headaches. My own experience: try to mix 3 PCIEX16 cards with 1 PCI card. Couldn't get the PCI card to work. Maybe due to other reasons, I am not sure. And perhaps mixing PCIEX1 and PCIEX4, X8, X16 is a different story than mixing PCI Express with PCI.

    From the following description from wiki:

    It seems that it's by design that you can plug an x1 card into an x16 slot (only go from low to high because of the physical pin-out constraint). Supposedly. I have no experience playing with it.

    But that brought in another consideration. Say you want to drive 8 monitors with 4 cards. Would you like to:

    Buy 1 x16 card, 1 x4 card and 2 x1 cards and use the above motherboard?

    Or buy a motherboard that has >4 x16 slots, and 4 x16 cards?

    With cards of the same kind, in the event of hardware problems you can switch cards around for trouble-shooting. If you stock a spare card, you only need to have one spare for all 4. Those are the added advantages.
  10. Make sure you have a power supply of at least 450W and if you need to run 8 displays you may need 550W.

    Also note the NVS 295 card has been supper seeded by the NVS 300 card. Which comes in PCI 1 or 16 versions and cables for Dual port/DVI/VGA. This card also is only rated at 17.5W. Should be widely
    available in a couple of months for around $120 (MSRP $149).
    #10     Jan 22, 2011